Principal Investigator/Program Director (Last, first, middle): Brown, Richard, Kenneth PROJECT SUMMARY Calorimetry, a universal detection technology, measures directly the heat released or absorbed by chemical reactions. Despite their potential range of applications, current microcalorimeters exhibit drawbacks that have precluded their use in the most current areas of biomedical research. These drawbacks derive from their relatively low sensitivity, requirement for large amounts of reactants and low throughput. Applications such as enzyme inhibition, screening for drug candidates, cell biology, proteomics, antibiotic profiling and clinical laboratory assays have been inaccessible to calorimetry. During Phase I of this grant, we developed a miniaturized high sensitivity stopped-flow microcalorimeter with a total reaction volume of 15L. This instrument has been shown to be able to measure enzyme activity and enzyme inhibition assays with as little enzyme as 10 picomoles. The miniaturization has been achieved by utilizing novel high-density thin-film thermoelectric sensors and a stopped-flow reaction cell design that eliminates the mechanical stirring that is present in all reaction calorimeters currently in the market. As the instrument measures directly the heat associated with the enzymatic reaction it does not require any chemical modification or labeling of the substrate, as is necessary in standard assays. The main goal of this Phase II SBIR is to transform the single-cell prototype calorimeter successfully completed during Phase I into a high throughput (1,200 samples per day) commercial ready multi-cell instrument with automated fluid handling, automated instrument operation and automated data processing, analysis and reporting. Since most targets for drug development are enzymes and the search for inhibitors is a major endeavor, we anticipate that the instrument to be developed in this Phase II grant will greatly facilitate and accelerate the drug discovery process and become widely adopted by the pharmaceutical and biotechnology industry.